tmp

var cluster = require('cluster');
var ping = require('ping');
var async = require('async');
var randomstring = require("randomstring");
var jsonfile = require('jsonfile')
var worker;

if (cluster.isMaster) {
    let file = './dict.json'
    let nums;
    let eod = false;
    let current = 0;

    jsonfile.readFile(file, function(err, obj) {
        nums = obj || {};
        start();
    })

    function start() {
        setTimeout(function again() {
            jsonfile.writeFile(file, nums, function (err) {
                if (!eod) {
                    setTimeout(again, 60 * 1000);
                }
            })
        }, 10 * 1000);

        for (let i = 0; i < 8; i++) {
            worker = cluster.fork();

            worker.on('message', function (msg) {
                if (current == 60466176) {
                    eod = true;
                    setTimeout(() => {
                        process.exit();
                    }, 60 * 1000)
                }
                nums[msg] = 1;
                current = Object.keys(nums).length;
                process.stdout.write((60466176 - current).toString() + "\r")
            });

        }
    }
} else {
    async.forever((cb) => {
        var num = randomstring.generate({
            length: 5,
            charset: 'alphanumeric',
            capitalization: 'lowercase',
        });
        process.send(num);
        setImmediate(cb);
    });
}